Bathythermograph data collected at fixed positions by weather patrol ships are being processed. Relationships between wind and changes in the mixed layer depth were studied. Cold outbreaks over the North Atlantic with accompanying northwesterly winds were associated with a positive change in the mixed layer depth (delta H); southerly and southeasterly flows indicated a negative delta H. Diagrams of evaporation vs wind speed appeared less satisfactory than those of air-sea temperature difference vs wind speed. A study of the heat budget of a column of ocean water suggested that a large amount of thermal-energy change is caused primarily by effects of horizontal advection and secondarily by lateral heat conduction; effects of precipitation on the column were assumed negligible. An evaluation of several methods of determining the heat vertically advected into or out of the column showed their unsuitability, alone, as forecasting techniques; however, an estimate of vertical advection appears necessary for inclusion in a forecasting procedure. A quantitative definition of the thermocline is proposed which gives physical boundaries based on points of tangency on the BT trace of 2 lines parallel to a characteristic line.